The application relates to a method and devices for the detection and/or determination of alkylating compounds, in particular of sulphur and nitrogen mustard gases.
The use of p-(4-nitrobenzyl)pyridine (NBP) as an analytic reagent for the detection of alkylating compounds is known in the art. Because many potential chemical warfare agents have alkylating properties this reaction has extensively been examined, in particular for the detection of mustard gases. Application of NBP in detection agents for mustard gases has never been quite satisfactory, however. The detection reaction is cumbersome, poorly sensitive and specific, temperature-dependent, while the reagents are poorly stable on prolonged storage. It is known in this field of art that additions like mercury cyanide, sodium perchlorate, sodium diethyl-dithiocarbamate and ethyl acetoacetate can be used to improve these qualities. Also by using nickel(II)-tetrakis p-(4-nitrobenzyl)-pyridine perchlorate complex on activated silica gel in a test tube, the said qualities need to be improved.
Also other reagents are suggested to replace NBP in the determination of alkylating agents; in particular with pyridine-4-carboxaldehyde 2-benzothiazolyl hydrazone, iodine and 1-iodo-butane might be detected very sensitively.
Nerve gases, which form a group of potential chemical warfare agents, possess, just as the organic phosphor insecticides and carbamates, which both are gaining ever-increasing economic importance, the property of acting as cholinesterase-inhibitors. Frequent use is made of this property for the detection of these compounds.
The anticholinesterases are brought into contact with the enzyme cholinesterase. After a certain incubation-time the remaining activity of the enzyme is measured by means of application of a substrate. The enzyme catalyses the hydrolysis of this substrate. Upon hydrolizing, the components to be measured are formed. When applying chromogenous substrates such as 2,6-dichloro indophenyl-acetate(DIBIA), immediately a blue coloured product is formed. Upon application of substrates such as .alpha.-naphthyl acetate, .alpha.-naphthol and acetic acid are formed. In so doing, the change in pH can be measured or the production of .alpha.-naphthol can be measured by adding "Fast Blue B-salt", which with .alpha.-naphthol forms a red-violet colour (see, for instance West-German Patent Application No. 2.062.710.